探讨Spring与Hibernate的整合所遇到的管理Session的问题

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转载最新推荐文章于 2026-08-24 16:43:14 发布 1.4k 阅读 AI 写同款· GEO 优化 ›

Spring和Hibernate整合事务配置之current_session_context_class hibernate.current_session_context_class设置原来配置事务模式： thread 会出现不存在激活的事务现象，主要原因是由于咋Spring管理事务中current session是绑定下springsessioncontext中的，而不是绑定在threadlocalsessioncontext中的。 hibernate.current_session_c 阅读详情

http://topic.youkuaiyun.com/u/20080704/14/bb2751bf-cd0a-4025-9e66-18f9031b1361.html

最近使用Struts1.3+Spring2.0+Hibernate3.2做了一个项目，最后测试时发现一个致命的错误，我的项目运行一段时间后，数据库直接down掉了。hibernate报了以下异常:

Java code

   
    2008
    -
    06
    -
    30
     
    19
    :
    00
    :
    02
    ,
    250
     WARN [com.mchange.v2.resourcepool.BasicResourcePool] 
    -
     com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@b27de5 
    --
     Acquisition Attempt Failed
    !!!
     Clearing pending acquires. While trying to acquire a needed 
    new
     resource, we failed to succeed more than the maximum number of allowed acquisition attempts (
    30
    ).

    2008
    -
    06
    -
    30
     
    19
    :
    00
    :
    02
    ,
    312
     WARN [org.hibernate.util.JDBCExceptionReporter] 
    -
     SQL Error: 
    0
    , SQLState: 
    null
    

    2008
    -
    06
    -
    30
     
    19
    :
    00
    :
    02
    ,
    312
     ERROR [org.hibernate.util.JDBCExceptionReporter] 
    -
     Connections could not be acquired from the underlying database
    !
    

    2008
    -
    06
    -
    30
     
    19
    :
    00
    :
    02
    ,
    328
     WARN [org.hibernate.util.JDBCExceptionReporter] 
    -
     SQL Error: 
    0
    , SQLState: 
    null
    

    2008
    -
    06
    -
    30
     
    19
    :
    00
    :
    02
    ,
    328
     ERROR [org.hibernate.util.JDBCExceptionReporter] 
    -
     Connections could not be acquired from the underlying database
    !
    
org.hibernate.exception.GenericJDBCException: Cannot open connection
    at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:
    103
    )
    at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:
    91
    )
    at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:
    43
    )
    at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:
    29
    )
    at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:
    420
    )
    at org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:
    144
    )
    at org.hibernate.jdbc.AbstractBatcher.prepareQueryStatement(AbstractBatcher.java:
    105
    )
    at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:
    1561
    )
    at org.hibernate.loader.Loader.doQuery(Loader.java:
    661
    )
    at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:
    224
    )
    at org.hibernate.loader.Loader.doList(Loader.java:
    2145
    )
    at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:
    2029
    )
    at org.hibernate.loader.Loader.list(Loader.java:
    2024
    )
    at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:
    375
    )
    at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:
    308
    )
    at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:
    153
    )
    at org.hibernate.impl.SessionImpl.list(SessionImpl.java:
    1106
    )
    at org.hibernate.impl.QueryImpl.list(QueryImpl.java:
    79
    )
    at cn.gcy.cyzd.impl.ItemDAOImpl.queryAll(ItemDAOImpl.java:
    15
    )
    at cn.gcy.cyzd.struts.action.IndexAction.list(IndexAction.java:
    54
    )
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.apache.struts.actions.DispatchAction.dispatchMethod(DispatchAction.java:
    269
    )
    at org.apache.struts.actions.DispatchAction.execute(DispatchAction.java:
    170
    )
    at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:
    425
    )
    at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:
    228
    )
    at org.apache.struts.action.ActionServlet.process(ActionServlet.java:
    1913
    )
    at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:
    449
    )
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:
    690
    )
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:
    803
    )
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:
    290
    )
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:
    206
    )
    at cn.gcy.cyzd.filter.EncodingFilter.doFilter(EncodingFilter.java:
    22
    )
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:
    235
    )
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:
    206
    )
    at org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:
    198
    )
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:
    75
    )
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:
    235
    )
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:
    206
    )
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:
    233
    )
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:
    175
    )
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:
    128
    )
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:
    102
    )
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:
    109
    )
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:
    286
    )
    at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:
    856
    )
    at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:
    565
    )
    at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:
    1509
    )
    at java.lang.Thread.run(Unknown Source)
Caused by: java.sql.SQLException: Connections could not be acquired from the underlying database
    !
    
    at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:
    104
    )
    at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:
    236
    )
    at com.mchange.v2.c3p0.PoolBackedDataSource.getConnection(PoolBackedDataSource.java:
    94
    )
    at com.mchange.v2.c3p0.ComboPooledDataSource.getConnection(ComboPooledDataSource.java:
    521
    )
    at org.springframework.orm.hibernate3.LocalDataSourceConnectionProvider.getConnection(LocalDataSourceConnectionProvider.java:
    81
    )
    at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:
    417
    )
    ... 
    46
     more
Caused by: com.mchange.v2.resourcepool.CannotAcquireResourceException: A ResourcePool could not acquire a resource from its primary factory or source.
    at com.mchange.v2.resourcepool.BasicResourcePool.awaitAcquire(BasicResourcePool.java:
    970
    )
    at com.mchange.v2.resourcepool.BasicResourcePool.checkoutResource(BasicResourcePool.java:
    208
    )
    at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:
    232
    )
    ... 
    50
     more

    2008
    -
    06
    -
    30
     
    19
    :
    00
    :
    05
    ,
    093
     WARN [com.mchange.v2.resourcepool.BasicResourcePool] 
    -
     com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@4c03d4 
    --
     Acquisition Attempt Failed
    !!!
     Clearing pending acquires. While trying to acquire a needed 
    new
     resource, we failed to succeed more than the maximum number of allowed acquisition attempts (
    30
    ).

这个错误郁闷了我很久，通过大家的帮助还有网络的大量资源我终于找到了其中的原因。首先说说我的daoimpl的写法
在daoimpl中我使用

Java code

   
    Query q 
    =
     
    super
    .getSession().createQuery(hql);

语句可以正常执行，但是在多次使用该语句后数据库有很多连接仍然没有断开！这是导致异常的关键所在，spring不是管理了session吗？这是为什么呢？
通过继承HibernateDaoSupport我们有两个选择：

Java code

   
    getSession().createQuery(
    "
    from Users
    "
    );
getHibernateTemplate().find( 
    "
    FROM Users);

网上找了找资料都是推荐用getHibernateTemplate，原因说的不是很清楚。

于是我做了如下测试：

分别循环调用getSession().createQuery("from Users");getHibernateTemplate().find( "FROM Users);
1000次
结果getSession()很快就包无法建立连接了。而getHibernateTemplate屁事没有可以跑完。

通过后台观察，使用getSession会在数据库中留下很多SQL*Net message from client的连接，终止测试后连接自动释放。
而getHibernateTemplate则从头到尾都使用一个连接。

难道是getSession()不会自动释放连接？

于是我又分别循环调用getSession().createQuery("from Users");getHibernateTemplate().find( "FROM Users);
5次
发现当前端程序一结束，getSession的5个连接立刻就释放了。结合前面1000次时终止测试后连接自动释放，可以说明getSession()是会自动释放连接的。

结论：
1、getSession()和getHibernateTemplate都可以自动释放连接（当然你的配置要正确），但是在一个线程内getSession会get很多个session（就是开很多个会话、连接），很可能导致数据库连接超过上限。所以推荐使用getHibernateTemplate。

2、如果有些语句无法用getHibernateTemplate实现，可以使用getHibernateTemplate.execute使用HibernateCallback回调接口。

另：可以设定HibernateTemplate的AllowCreate为True，并在finally中关闭Session。也可以将true作为参数传递到super.getSession(..)方法中取得Session。这样也可以，就是麻烦点。
参见：
http://springframework.org/docs/api/org/springframework/orm/hibernate3/HibernateTemplate.html
http://www.mxjava.com/blog/article.asp?id=246
参考资料：http://blog.sina.com.cn/s/blog_50e4caf70100a1nx.html

于是，如果我们一定要书写hql语句可以参考如下形式

Java code

   
    public
     PageUtil getLog(
    final
     Long userid,
    final
     Integer page) {
                String counthql
    =
    "
    select count(mod) from Blog mod where mod.userinfo.userid=?
    "
    ;
                Integer count
    =
    (Integer)getHibernateTemplate().find(counthql, userid).get(
    0
    );
                
    final
     PageUtil pu
    =
    new
     PageUtil();
    //
     分页包装类
    

                    pu.setCount(count);
                pu.setPage(page);                
                pu.setMaxPagesbyCount(count);                
                List li
    =
     getHibernateTemplate().executeFind(
    new
     HibernateCallback(){
                        
    public
     Object doInHibernate(Session session) 
    throws
     HibernateException, SQLException {
                                String hql
    =
    "
    from Blog mod left join fetch mod.userinfo where mod.userinfo.userid=? order by mod.logid desc
    "
    ;
                                Query query
    =
    session.createQuery(hql);
                                query.setParameter(
    0
    , userid);
                                query.setMaxResults(pu.getMaxResults());
                                query.setFirstResult(pu.getFirstResult());        
                                
    return
     query.list();
                        }                        
                });                
                pu.setResults(li);
                
    return
     pu ;
        }

只有这样做了以后才能确保数据库的连接能够尽早被释放，项目不至于崩溃。

____________________________________________________

解决办法1 this.releaseSession(session);
解决办法2 hibernate.connection.release_mode=auto
解决办法3 getSession(false);

不妨可以再测试一下

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